Hodgkin and Huxley model The Nobel Prize in

Hodgkin and Huxley model The Nobel Prize in Physiology or Medicine 1963 was awarded jointly to Sir John Carew Eccles, Alan Lloyd Hodgkin and Andrew Fielding Huxley "for their discoveries concerning the ionic mechanisms involved in excitation and inhibition in the peripheral and central portions of the nerve cell membrane". Alan Lloyd Hodgkin Andrew Fielding Huxley Their work (published in 1952) led not only to a better understanding of the physiology but to the development of new mathematical techniques. Their model is still the basis of many other neural and cellular models today.

Schematic description of a neuron A neuron is a cell. It shares many properties with many other cells but it has the unique property of being able to transmit electrical signals over long distances.

The giant axon of the squid

Chemical composition of extracellular and intracellular fluids From: Textbook of Medical Physiology by Guyton & Hall

Diffusion through cell membrane Lipid bilayer

Simple diffusion due to concentration difference

Simple diffusion due to concentration difference a(CL-CR) CL – Concentration on left side CR – Concentration on right side

Factors that affect Net Rate of Diffusion Concentration difference Effect of membrane electrical potential Pressure difference

Selective diffusion

Transport of sodium and potassium ions

Facilitated diffusion

Active transport: sodium-potassium pump

Active transport: co-transport of sodium and glucose

The giant axon of the squid

The Hodgkin-Huxley Equations From: Nonlinear Dynamics in Physiology and Medicine by Anne Beuter, Leon Glass, Michael C. Mackey and Michele S. Titcombe (Editors).

Voltage-gated sodium and potassium channels

Nerve action potential

Propagation of action potential

Schematic description of a neuron A neuron is a cell. It shares many properties with many other cells but it has the unique property of being able to transmit electrical signals over long distances.